EB338

I have been doing a lot of homework and no small amount of searching for the european 928S 16v big valve cylinder heads. I was told that the 2v 944 cylinder heads have the same big valves and bolt right up with minimal modification. (minimal modification being a relative term I am sure).

Has anyone seen or done this? What modification is required?

Do the 2v 944 heads have the same ports and flow capacity as the euroS heads in addition to the same size big valves?

Are all 2v 944 heads created equal or is there a particular head that equals the Euro 928S heads?

Can the 944 heads be ported/modified as much as the Euro 928S heads?

Is the cam drive and related components the same as well?

This would seem to be a much easier thing to find than the Euro 928S heads yet I havent seen or heard much about the swap so I figured there had to be something different or difficult to keep this from being a common practice.

Rich9928p

I haven't done it, but I've seen the heads side by side. It would be "relatively easy" to convirt 944 heads for use in a 928 track car where you don't worry about the heater and smog stuff. Off the top of my head I remember something would have to be ground off the 944 head and a water channel would be capped off.

Do the 2v 944 heads have the same ports and flow capacity as the euroS heads in addition to the same size big valves?

YES

Are all 2v 944 heads created equal or is there a particular head that equals the Euro 928S heads?

all 944 heads have larger valves (same size as 928 Euro S)

Can the 944 heads be ported/modified as much as the Euro 928S heads?

YES

Is the cam drive and related components the same as well?

No. You would need to use 928 cams and cam towers

Ian928

I may have a set for sale if you are interested in shipping them from Norway. PM me if you are interested.

slate blue

Don't do it, I will elaborate further later, but the valves have different spacings and as such the cams will need to be different too.

Cheers Greg

Ian928

Sorry, I have a set of 928S Euro heads (1980), not 944.

EB338

What about 968 heads? Can they be bolted on our V8s in similar fashion? I have been told the 4v 944 heads are a more direct bolt on than the 2v heads, burt how different are the 968 heads? Can they be made to bolt up? Same valve and port sizes and configurations??

Greg Gray: Care to elaborate on the different valve spacing and reasons why not to adapt the 944 heads? Im also very interested on your head flow figures thread Im moving a similar direction.

Ian928

It has been done already by Sterling(maybe he will see this thread and chime in)! But check out his homepage: http://www.928sg.com/

Edit: Sterling has adapted the Variocam to 928 heads, not 968 heads to a 928 block.

EB338

Right, Ive seen his site and he has been involved in another thread I have posted in. My question here was about the use of the entire 968 head on the 928 block, not just the adaptation of the variocam system to the 928 heads.

Vilhuer

968 intake valves are larger than S4 and later 928. Other than different mounting point for cam chain tensioner 968 heads are same as 944 S and S2. So they are equally easy to install into 928.

Entire 944/968 engine is 1/2 of 928. This means all parts that Porsche could keep same are same. All differences have some enginering reason behind it. This includes raw castings also. If same casting could be used, even though end result was different, it was used. Financially it didn't make sense for Porsche to make two separate parts if they could get away with one.

EB338

So what about 968 port and valve sizes? I assume they are bigger since I have heard more than one mention of adapting 968 valves into 928 heads. How much porting can they handle? Can you modify a 968 head equal or beyond a 32v 928 head? How do the heads themselves compare to the 928 heads? Were all 968 heads Variocam? Were any of them Variocam Plus systems or is that a strictly new 911 development?

EB338

Also what other Porsche models share this basic interchangeability? 928, 944, 968.......any others?

Vilhuer

All 968 heads were same basic first version of Variocam. Intake valves are 2mm larger in diameter compared to S4 and later 928. Exhaust valves are same. Other than that heads are very similar if not identical compared to GTS heads.

John Veninger

EB338,

Lots of your questions can be answered by a simple search of the archives.

EB338

Im a relative new guy here, how and where do I do that? Is it the search link on the bar at the top of the page or are the archives someplace else?

John Veninger

You can use the search link and go to advance. This way you can just search the 928 Forum. Lots of good stuff that may help you.